Chinese vaccines not as effective

BEIJING — In a rare admission of the weakness of Chinese coronavirus vaccines, the country’s top disease control official says their effectiveness is low and the government is considering mixing them to get a boost.

Chinese vaccines “don’t have very high protection rates,” said the director of the China Centers for Disease Control, Gao Fu, at a conference over the weekend in the southwestern city of Chengdu.

Beijing has distributed hundreds of millions of doses abroad while trying to promote doubt about the effectiveness of the PfizerBioNTech vaccine made using the previously experimental messenger RNA, or mRNA, process.

The vaccine produced by Cambridge-based Moderna also uses the mRNA process.

“It’s now under formal consideration whether we should use different vaccines from different technical lines for the immunization process,” Gao said.

Officials at a news conference Sunday didn’t respond directly to questions about Gao’s comment or possible changes in official plans. But another Chinese official said developers are working on mRNAbased vaccines.

“The mRNA vaccines developed in our country have also entered the clinical trial stage,” said the official, Wang Huaqing. He gave no timeline for possible use.

Experts say mixing vaccines, or sequential immunization, might boost effectiveness. Researchers in Britain are studying a possible combination of PfizerBioNTech and the traditional AstraZeneca vaccine.

Vaccines made by Sinovac, a private company, and Sinopharm, a state-owned firm, have made up the majority of Chinese vaccines distributed to several dozen countries including Mexico, Turkey, Indonesia, Hungary, Brazil and Turkey.

The effectiveness of a Sinovac vaccine at preventing symptomatic infections was found to be as low as 50.4% by researchers in Brazil, near the 50% threshold at which health experts say a vaccine is useful. By comparison, the Pfizer-BioNTech vaccine has been found to be 97% effective.

‘It’s now under formal consideration whether we should use different vaccines ...’

GAO FU director of the China Centers for Disease Control

Getty iMaGes FiLe NOT VERY EFFECTIVE: A woman is inoculated with the CoronaVac vaccine, developed by China’s Sinovac laboratory to ward against COVID-19, at a vaccination center at Carrasco airport in Uruguay on April 8.